This invention relates to a round baler having a set of flexible bale forming elements, useful to form two bale forming chamber sections between side walls and trained over fixed and moveable rolls having at least one conveyor acting with the bale forming elements to cover substantially the circumference of at least one of the bale forming chamber sections and having rotatable arms to carry some of the moveable rolls.
EP-A1-0 064 117 discloses a round baler formed as a so-called non-stop baler. This round baler provides an upstream bale chamber and a downstream bale chamber surrounded by an upper and a lower conveyor. The upper conveyor comprises a single set of belts routed side-by-side over a series of fixed and moveable rolls. Three major moveable rolls are carried on a rotatable carrier at three equidistant locations. The spans of the belts between the major rolls are moved with the carrier from the front to the rear and form part of the bale chambers. A gate is provided in which rolls are kept in fixed positions to guide another run of the belts.
The problem to be solved with respect to this prior art baler is the limitation of the bale diameter by the distance between the major rolls. Another problem is the complexity of this design due to the high number of rolls needed in total. Yet another problem is the need to rotate the carrier inside the bale chamber which requires to double the side walls with discs to support the rotating rolls, as simple arms would interfere with the bale. More uncertain even is the transfer of the bale from one belt span to the next during the process.
According to the present invention, there is provided an improved arrangement for supporting flexible bale-forming elements of a non-stop, large round baler.
An object of the invention is to provide an arrangement for supporting flexible bale-forming elements including moveable arms mounted so as to permit relative movement between their respective free ends such as to allow them to reach large bale diameters, at least in the bale chamber concluding the bale cycle, whereas the bale chamber acting as an auxiliary bale chamber may be kept small.
A more specific object of the invention is to arrange the arms such that the segment of the flexible bale-forming elements that span between adjacent rolls supported by the arms creates a loop which will form a chamber surrounding a substantial portion of the forming bale in a much simpler way than using a multitude of rolls to provide walls of a bale chamber. Furthermore, the density reached with a loop around a bale is much higher than that reached with spans covering the bale only partially. The flexible bale forming elements may consist of belts or chains and slats.
Yet another object of the invention is to provide a bale chamber defined in part by opposite side walls, the periphery of which is not connected to surrounding structure, such as to allow the moveable rolls to move outside the bale chamber. In such a design the side edges of the belts or other flexible bale forming elements come quite close to the inner face of the side walls and, thus, avoid losses of crop and plugging problems. Furthermore, this feature enables the side walls to be moved laterally, so as to either change or adjust the friction between a bale and the side walls and/or to change the width of a bale formed in the bale chamber.
Although it is possible to have the arms inside the bale chamber, arms rotating outside the bale chamber are simple to control, avoid friction, (since no crop can squeeze between them and the side wall), and have freedom to move and allow the moveable rolls to be mounted so as to extend beyond the side walls. Arms moving through the space between the side walls would need to be journalled on a bearing outside the periphery of the side walls and should be extendable to a larger extent than arms being journalled within the periphery of the side walls.
Rolls extending beyond the side walls allow the width of the bale chamber to be selectively increased. Side walls which can be moved laterally, i.e., in the direction of the width of the round baler, enable making bales of different width or the friction between the walls and bale to be reduced when ejecting the bale.
The size and location of the bale chambers as well as the tension in the bale forming elements can be controlled, if the arms are formed of multiple parts which are adjustable with respect to each other by means of a power actuator. For example, the arms may be lengthened or shortened, tilted, bent or the like, to guide the rolls over which the bale forming elements are trained in a certain pattern.
One way to adjust the effective length of the arms is to connect its parts like a telescope, e.g., one part may be in the form of a tube, with another part being slidably received in the first part.
Another way to change the arms is to connect its parts in a joint, which allows the various parts of the arms to assume a position which brings the moveable rolls to the place necessary to create the one or other bale forming chamber.
Individual drives for each arm allow them to be positioned independently of each other and for electronic controls to be used to determine their position. Such drives may exist in belt or chain drives, in mechanical transmissions, including planetary gears, hydraulic drives, etc., and are controlled depending on the size of the bale, the operation step it currently undergoes, etc.
While it would be possible to change the position of the arms according to a control device without any feed-back signals, it is more sophisticated to use sensors to constantly compare the relationship between the size of the bale and the position of the arms. This feature allows the bale to be well surrounded by the belts and to eliminate excessive tension in the belts and the parts carrying them.
One way to make use of the signals emitted by the sensors is to feed them into a hardware electric circuit. More flexibility is obtained though by using a controller based on software, since it is more simple to react to different situations and to activate the power actuators accordingly.
The number of parts involved is kept low and the relationship between the arms and the sidewalls remains unchanged, if the part connecting the side walls to the chassis and the part bearing the arms is the same, namely an axle. This axle may comprise a strong and rigid tube withstanding the bending and torsion forces applied on it. Since this tube does not obstruct the path in which the arms move, it may have a considerable diameter, like 0.5 m, which is sufficient to support the load.
Rotating all arms about the same axis avoids a conflict between one arm and the axle on which another arm is journalled or with the other arm itself.
Filler plates between the lower edge of the side walls are helpful to avoid crop losses and to keep the shape of the bale uniform. Furthermore, they avoid friction of the bale side faces when they slide over the edge of the side wall.
In order to facilitate the movement of the arms through the gap between the lower edge of the side walls and the bottom conveyor, the filler plates are moveable too. One manner in making the filler plates moveable is to construct them in sections, with certain sections of the filler plates being moveable outwardly and inwardly with respect to the side walls so as to let the rolls and arms pass by. Another way would be to move the filler plate sections along and together with the arms and also to move them from the rear to front in a revolving cycle. Whichever solution is chosen, the position of the arms is used in controlling the position of the filler plates or of its sections.
Since the shape and the size of the side walls is determined by the location and size of the round bales produced between them, the rolls supported between the free ends of the arms guide the bale forming elements along respective portions of the edges of the side walls. Thus the periphery of the side walls is an excellent place to provide a track for the rolls or the arms. The periphery may by provided with covered or uncovered rails, tracks or the like for that purpose. Alternatively the track, for example a bent, profiled or formed rail, tube, carrier or the like may be attached rigidly to the side wall.
Three arms are an efficient number to support rolls having flexible bale forming elements extending between them for creating two bale forming loops between them.
While one roll at the end of each set of arms may be sufficient to carry the flexible elements, such as belts, and while three or more rolls may be used to control the movement of the bale forming elements, two rolls are appropriate to guide and carry the elements, and, depending on the radial distance between them, are helpful to determine the distance of the loops for forming the bale chambers.
If one bottom conveyor is assigned to each bale forming chamber, i.e., underneath the bale forming elements in the front and the rear, each of them may be designed according to its functions. Whereas a rear bottom conveyor only has to cover the bottom end of the bale forming chamber, the front bottom conveyor has to assist in the start of the bale. For this reason, the bottom conveyor immediately downstream of a pick-up assembly is inclined upwardly and forms a wedge with a span of the bale forming elements.
One means to provide for the proper tension in the bale forming elements which provides for a good tracking and a high density in the bale is to have at least one moveable roll on an arm applied by a biasing force. The biasing force may come from a spring, a hydraulic circuit, a pressure vessel or the like.
Such a new round baler is useful also to tie or wrap a produced bale if a wrapping or tying mechanism is provided near the downstream bale chamber to feed net, plastic or twine between the rear bottom conveyor and the bale forming elements.
The density of the crop may be increased and the quality may be improved if the crop is cut by using a cutting means, since this allows a higher compaction.
Flexing of the side walls can be limited or decreased if a support is used, which provides for a rigid connection between the chassis and the side walls. Such support can be a link, a hydraulic actuator or the like.
Another way to avoid an outward bending of the sidewalls under high pressing forces is the use of stops on the rolls, the arms carrying them or a brace bridging the arms, which stops slide or roll along the outside of the side walls and restrain them from bending outwardly.
One alternative way to control the movement of the rolls on the arms is to use a track, which controls the movement of that part of the arm, which carries the rolls.
While conventionally the flexible bale forming elements are arranged above a bottom conveyor or above a pick-up assembly, this is not absolutely necessary. It is possible too, to feed a bale forming chamber between bale forming elements also from the top. This would provide for a longer path between the pick-up assembly and the inlet for crop processing, like cutting and adding additives, and it would be easier to carry the weight of the bale. Reference is made also to already existing machines having the feeding on the top.
Using the existing pick-up assembly to close the bale forming chamber just being fed at the bottom, render another bottom conveyor superfluous. Thus cost savings and a higher reliability may be achieved.
There are two ways to close the bale forming chamber, which is currently fed, by means of the pick-up assembly. One is to move the inlet of the bale forming chamber to a location above the pick-up assembly. Another is to move the pick-up assembly accordingly. Movement may be accomplished by using hydraulic motors and tracks, links or the like.